Terry Jones studied medieval literature at Oxford, where he met classmate Michael Palin. They both went to work at the BBC, and joined several not-yet-discovered stars, including Graham Chapman, John Cleese, Marty Feldman, and Eric Idle, writing for The Frost Report, a satirical news half-hour with David Frost. After writing for several other series, Jones stepped in front of the camera to perform in an increasingly Pythonesque ensemble for two years on Do Not Adjust Your Set. As that show ended, Monty Python's Flying Circus began, with Chapman, Cleese, Idle, Jones, Palin, and the program's only American, Terry Gilliam.

Fellow Pythons say Jones was among the most involved in the program's writing, had a fervent drive for perfection, and frequently butted heads backstage with John Cleese. In early clashes with BBC, Jones fought ferociously to keep the program true to its original anarchic intent, and succeeded. Monty Python famously skewered everything good and right about western civilization, became a smash hit on both sides of the Atlantic, and still remains both popular and influential. Even as the original Monty Python was still in production, Jones also wrote comedy for The Two Ronnies, and he wrote, with Palin, an episode of the anthology Black and Blue combining chocolate and cannibalism for laughs. Fifteen years later, the teleplay from that episode was expanded into the feature film Consuming Passions with Jonathan Pryce.

Monty Python's Flying Circus ran five seasons and spawned several movies, with Jones and Gilliam sharing directing duties on Monty Python and the Holy Grail and The Meaning of Life, and Jones alone helming The Life of Brian. His career as a film director sputtered post-Python, with three features that were quite good but poorly received: Personal Services is a serious comedy with Julie Walters as a whorehouse madam with a heart of gold, but it is a complete departure from all things Python. The more slapstick and enjoyably absurd Erik The Viking is based on Jones' children's book, and stars Tim Robbins and Mickey Rooney. The last film Jones directed was The Wind in the Willows (released on video as Mr Toad's Wild Ride), a family fantasy with Jones himself as Mr Toad and Steve Coogan as the mole, but it was produced for the Disney Corporation, then sold to another studio and haphazardly released with little publicity.

Jones wrote the dead-serious and scholarly Chaucer's Knight: Portrait of a Medieval Mercenary, the non-fiction Who Murdered Chaucer? A Medieval Mystery, and contributed to the Discovery Channel's Hidden History of Egypt. He has written several children's books, including The Curse of the Vampire Socks, The Beast with A Thousand Teeth, and with co-author Palin, Dr Fogg's Encyclopaedia of All Knowledge. He also hosted the lighthearted Medieval Lives on BBC, and wrote the screenplay for Jim Henson's engaging big-screen Labyrinth, starring David Bowie and Jennifer Connelly.

He has also written numerous columns for Britain's Guardian and Observer, lambasting Tony Blair, George W. Bush, and their invasion of Iraq. "Tony Blair's dedication to carrying out the policies of the White House," Jones wrote in 2002, "proves time and again that he has the courage of their convictions."

Now in his 60s, Jones suffers from arthritis and walks with a cane. In October 2006, he was diagnosed with colon cancer, but it was not enough to keep him from attending the London premiere of Spamalot, the play based on Monty Python and the Holy Grail, starring Tim Curry. The next morning Jones underwent cancer surgery, and explained in a brief press release, "Unfortunately, my illness is not nearly bad enough to sell many newspapers, and the prognosis is even more disappointing." In 2015, Jones was diagnosed with frontotemporal dementia, and with the support of friends remains active.